Hydraulic shock absorber



Nov. 5, 1935. M,HoUDA!| E I 2,019,974

HYDRAULIC SHOCK ABSORBER .Filed July 9, 1934 gl/ z 4 "mijn :5..- lll/11111.

Patented Nov. 5, 1935 UNlTED STATES PATENT OFFICE HYDRAULIC SHOCK ABSORBER Application July 9, 1934, Serial No. 734,327, In France October 2, 1933 Claims. (Cl. ISS-89) My invention relates to hydraulic shock absorbers which are particularly adaptable for use on automotive vehicles for damping and absorbing road shocks during travel of the vehicle.

x5 An important object of the invention is to produce a hydraulic shock absorber of the rotary piston type in which the piston shaft projects at each end from the shock absorber body.

A further object is to provide in the type of shock absorbers referred to separate valve assemblies, one of the assemblies to meter and control the hydraulic fluid flow in the shock absorber for damping and absorbing shocks when the vehicle springs are flexed by movement of the vehicle body and axle toward each other, and the other assembly to meter and control the hydraulic fluid flow for damping and absorbing the recoil of the vehicle springs when. the vehicle chassis and axles move away from each other.

Another object is to provide separate valve assemblies located in the axial bore of the piston structure and separately manually adjustable from the exterior of the Vshock absorber.

Still a further object is to utilize the type of shock .absorber referred to in individual wheel suspension and included in a suspension linkage quadrilateral with the shock absorber shaft connected at its ends with one of the links of the linkage and serving as a pivot support for such link.

Still a further object is to provide simplied and economically manufactured and -assembled structure for shock absorbers of this type, anda structure which will accommodate automatic regulation of the valve assemblies as by means of thermostat elements.

The various features of the invention are incorporated in the structures disclosed on the drawing, in which drawing Figure 1 is a sectional elevation on plane .I-I of Figure 2;

Figure 2 is a cross-section on line II-II of Figure 1 and Figure v3;

Figure 3 is a section on plane III- III of Figure 2;

Figure 4 is a diagrammatic elevation showing the inclusion of the shock absorber structure in a linkage quadrilateral for independent support of a vehicle wheel;

Figure 5 is an enlarged plan View of theshock absorber shown in Figure 4. Y

Referring to Figures 1 to 3, the shock absorber has the cylindrical tubular body I which is counter-bored at its ends yat 2 and 3 to have a somewhat greater diameter in order to provide at 4 and 5 shoulders against which the end walls or caps 6 and 'I may be applied in a manner to be explained more in detail later.

The space in the interior of the tubular body I 5 is divided into twoparts by fixed partition walls i2 and I3. These fixed partition walls have the outer cylindrical surfaces I4 which accurately engage and t the inner side of the body wall I, and at their inner ends the partition walls are l0 closely engaged by the hub I5 of the piston structure from which hub shaft ends I6 and I'I extend through the end walls 6 and l, these shaft ends being journaled in the end walls and the extensions I8 thereon.

The partition walls I2 and I3 have the grooves I3 and 23 respectively which serve various purposes. They receive the bolts 2l and 22 which pass through suitable holes in the end walls 6 and 'l and secure these end walls securely against 20 the shoulders 4 and 5 and the sides of the partition walls.

Channels 25 and 26 are provided in the partition wall I3 and channels 27 andr28 in the partition Wall I2 in order to establish communication 25 between the grooves I9 and 26 and the working chambers of the shockY absorber. The channels 21 and 28 are provided with flap valves 29 and 29 anchored on the lower partition wall I2 as indicated by O and O', Figure 1 and arranged in 30 such a manner that they open up when a partial vacuum is produced in the working chambers A and B and the valves close when pressure prevails in these chambers. Capillary passages 25 and 26 are provided in the upper partition wall I3 35 for the escape of air which might be trapped or mixed with the fluid in the upper working chambers K and L,

The grooves I 9 and 26 terminate in front of Aother passages 3|, 32, 33 and 34 provided in the 40 end walls`6 and 'I in such manner that the grooves I9 and 26 communicate with the replenishing chambers C and D formed by the covers I6 and I I secured to the ends of the body wall I and surrounding the shaft ends I6 and Il. Through 45 the passages 3| and 34 iiuid may ow from the reservoirs to the groove I9 and from there through the passages 21 and 23 into the lower working chambers A and B for fluid replenishment. 'I'he upper passages 32 and 33 intersect 50 radial channels 35 and 36 in the end walls 6 and 'I respectively which radial channels communicate with the internal bores 31 and 38 in the walls A6 and I through peripheral grooves 39 and 46 respectively, any leakage along the shaft ends 55 being thus returned to the uid reservoirs C and D.

The covers I0 and I I by holding packing 39' and tightly against the shaft ends and the ends of the Wall extensions I8 prevent escape of fluid along the shaft ends to the exterior of the shock absorber.

To the opposite ends of the piston shaft are secured levers 4I and 42 which at their outer ends are usually secured to the axle structure while the shock absorber body I is secured usually to the vehicle chassis.

. The piston structure hub I5 has two blades or wings 43 and 44 diametrically opposite each other with their ends bearing against the inner face of the cylindrical body wall I. The shaft ends I6 and I1 havethe axial bores 45 and 46 respectively extending therethrough from the outer end thereof but terminating short of communication with each other. In these bores are located the valve assemblies for controlling and metering the fluid ow during operation of the shock absorber. Any suitable type of valve assembly may be utilized, adjustable manually, or automatically by thermostatic means. As shown, the bore 45 receives a member 41 extending between a head 41' and a valve 49, and this member 41 may be a continuous rigid stem or a thermostatic device, the head 41' being threaded in the outer end of the bore 45 whereby the valve structure may be longitudinally adjusted for setting of the valve 49 relative to the seat X between the inner end E of the bore 45 and the reduced inner end F. A

similar adjusting member 48 is provided in the' bore 46 connecting with the valve 5D for cooperating with the seat Y between the inner end G of the bore and the reduced end H.

A passage 5I is drilled diametrally through the piston hub I5 to intersect the reduced end or chamber F and connect the working chambers K and B with this valve chamber F. Another passage 52 is drilled diametrally through the piston hub to intersect the reduced bore or valve chamber H for connecting this chamber with the working chambers A and L. Extending through the piston hub and the piston vanos 43 and 44 are the passages 53 and 54, both opening into the valve chamber E, and other passages 55 and 56 in the hub and vanes open into the valve chamber G. 'I'he passage 53 communicates at its outer end through a port with the working chamber A where it is normally closed by a valve 51 which opens only when there is negative pressure in the chamber A. 'Ihe passage 55 communicates with the working chamber K through a port which is normally closed by a valve 58 which opens only when there is negative pressure prevailing in the chamber K. The passage 54 communicates with the chamber L through a port which is normally closed by a valve 59 which opens only when negative pressure prevails in the chamber L and the passage 56 communicates with the working chamber B through a port normally closed by the valve 60 which opens only when negative pressure prevails in the chamber B. By virtue of the passage 5I connecting the working chambers K and B, these chambers are simultaneously under either pressure or vacuum, and similarly the chambers A and L connected by the passage 52 are simultaneously under either pressure or vacuum.

, Describing now the operation, suppose that the working chambers K and B are the low pressure chambers from which the uid is forced during bump strokes of the shock absorber as when the vehicle chassis and axle approach each other and that the chambers A and .L are the high pressure chambers from which the fluid is forced during rebound strokes of the shock absorber as when the springs recoil or rebound. During a bump stroke the piston structure rotates in clockwise direction (Figures 2 and 3). During such rotation of the piston the valves 58 and 6i) will be closed by the pressure so that the only outlet for the iiuid from the chambers K and B will be through the passages 5I to the valve chamber E at one side of the valve 49, then past the passage defined by the valve to the valve chamber E,

then through passages 53 and 54 and past the valves 51 and 59 to the high pressure chambers 15 A and L, the valve 49 then determining the resistance to the fluid iiow during such bump strokes of the piston structure.

During recoil strokes of the piston structure,

it will rotate in counter-clockwise direction, the 20 valves 51 and 59 being then held closed by the pressure, and the only outlet of the fluid being then through the passages 52 to the chamber H, then past the valve 50 to the valve chamber G,

and from there through the passages 55 and 56 25 and past the valves 58 and 69 to the low pressure I chambers K and B. The valve 50 thus controls resistance to flow during rebound strokes of the piston structure. The valve assemblies may be separately and independently set and adjusted 80 manually for the desired control of the fluid ilow and, if thermostat elements are applied to the valves, the valves will be independently thermostatically adjusted to compensate for Variations in the temperature and viscosity of the fluid.

The two replenishing chambers or reservoirs C and D are connected together at the bottom through the passages 3I and 34 and the groove I9, and these replenishlng chambers may be provided with ller openings closable by plugs 6I and a) vehicle chassis 61 as by brackets 68 and the arms I0 4I and 42 extending from the Shaft ends I6 and I1 converge and are pivoted at their outer ends, as indicated at 62, to the upper end of the element 64 which supports the axle 69 for a vehicle wheel W. At its lower end the member 64 has 55 pivoted thereto at 65 the outer end of the vehicle spring 66. The member 64 forms the outer link of the suspension linkage quadrilateral, the spring 66 forming the lower resilient link, and the arms 4I and 42 constitute the upper link, the shock 00 absorber shaft forming the pivot connection between this upper link and the vehicle chassis.

The arms 4I and 42 are held to the shaft ends I6 and I1 byv nuts 'I9 which are hollow to accommodate adjusting members 1I connecting with the adjusting heads 41 and 48 of the valve assembly, these adjusting members 1I being turnable as by means of a screw driver for manual setting of the valves from the exterior of the 70 shock absorber. Independent manual setting of the valve structures may thus be readily and easily accomplished.

I have shown a practical and efficient embodiment of the various features of my invention, but 76 I do not desire to be limited to the exact construction, arrangement and operation shown and described as changes and modications are possible which would still come within the scope of the invention. l

I claim as my invention:

1. A hydraulic shock absorber comprising a cylindrical annular wall, end walls cooperating with said annular wall to define a cylindrical space for hydraulic fluid, partitions extending between said walls into said space, said partitions having longitudinal grooves, bolts extending through the end walls and said grooves for locking said end walls and annular wall together, a piston structure operable in said space and having shaft ends extending through said end walls to the exterior thereof, passageways through said piston structure for the flow of hydraulic uid, valve structures in said passageways for controlling the flow therethrough, fluid reservoirs formed adjacent said end walls and having upper and lower passages therethrough communicating with the grooves in said partitions, replenishing passages through the lower partition for the iiow of replenishing fluid from said reservoirs to said space.

2. A hydraulic shock absorber comprising a cylindrical annular wall, end walls cooperating with said annular wall to define a cylindrical space for hydraulic fluid, partitions extending between said walls into said space, said partitions having longitudinal grooves, bolts extending through said grooves for locking said end walls and annular walls together, a piston structure operable in said space between said partitions to displace the uid, valve means for controlling the flow of the displaced fluid, a fluid reservoir communicating with said grooves, and a fluid replenishing connection between one of said grooves and said space.

3. A hydraulic shock absorber comprising a cylindrical annular wall, end Walls cooperating with said annular wall to dene a cylindrical space for hydraulic fluid, partitions extending between said walls into said space, said partitions having longitudinal grooves therethrough, bolts extending through said grooves for holding said end walls in place, a piston structure o-perable in said space between said partitions to displace hydraulic fluid, valve means for controlling the flow of the displaced uid, fluid reservoirs formed adjacent said end walls and inter-connected through said grooves, and a replenishing connection from one of said grooves to said space.

4. A hydraulic shock absorber comprising a cylindrical annular wall, end walls cooperating with said annular wall to define a cylindrical space for hydraulic uid, upper and lower partitions extending between said walls into said space, said partitions having longitudinal grooves therethrough, bolts extending through said grooves for holding said end walls in place, a fluid reservoir adjacent one of said end walls communicating with said grooves, check valve controlled passages through the lower partition for connecting the corresponding groove with said space for the flow of replenishing iiuid, and air vent passages through the upper partition connecting the cor.- responding groove with said space.

5. A hydraulic shock absorber comprising a cylindrical annular wall, end walls cooperating with said annular wall to define a cylindrical space for hydraulic fluid, partitions extending between said walls into said space, said partitions having longitudinally extending passageways therethrough, bolts extending through said passageways for securing said end walls in place, a piston structure operable in said space between said partitions to displace the fluid, valve means for controlling the flow of the displaced fluid, a iluid reservoir adjacent each end wall and communicating with the respective ends of the passageways to be thereby inter-connected, and connection between one of said passageways and said space for the flow of replenishing fluid.

MAURICE HOUDAILLE. 

